Improvement in pneumatic engines



N N lvrrnn STATES A valves.

i PATENT ort-11er.

"JOHN r. HAsKINs, or FITCHBURG, MASSACHUSETTS.

INI PROVEMENT IN PNEUMATIC ENGINES. .I

` i Specification forming part of Letters Patent No. 115,198, dated May23, 1871.

Toall whomt may concern:

Be itkn'own that I, JOHN F. HAsKINs, of Fitchburg, in the county VofWorcester and State of Massachusetts, have invented an Improvement inPneumatic Engines; and I do hereby "deolarelthat the following, taken inconnection with the drawing which accompanies and forms part of thisspecification, is a description of my invention sufficient to enablethose skilled inthe art to practice it.

December 14,1869, Letters Patent of the United Statesywere granted toRobert Spear, of New Haven, for his invention of an engine operated bycompressed air to raise water, in whioh'he` use's a vertical cylinderwith a hollow buoyant float or piston, the movement of which operatesthe valves to admit water and air alternately.

" p. `My invention maybe stated as an improvement upon Spears, in that,instead of opening the air inlet and exhaust valves simultaneously, asSpears does, or proposes to do, I close my air-exhaust valve before Iopen my air-inlet valve'when beginning to force water out of the engine5 and when filling the engine with Water I shut my air-inlet valvebefore I open my air-exhaust valve, and thus 'I prevent loss ofcompressed air, which occurs in engines made asspecified in Spearsaforesaid patent, which engines do not operate practically, because theair-inlet and air-exhaust valves being opened at the same time thecompressed air passes directly from the inlet-pipe into the cylinder andout of the open exhaust-valve, and blows to waste without overcoming theresistance which the water oiers to elevation. In my invention I keepthe cylinder and guided buoyant piston described by Spear, and

place on the piston-rod tappets, which operate against parts which areconnected with the air inlet and exhaust valves to open and close saidEach air-valve is worked from a rocker-shaft having 'thereon tworocker-arms, one bearing an elevated weight, by which the val-ve isopened or closed when the weight is moved y slightly one way or theother out of the vertical plane passing through the rocker-shaft. Theother rocker-arm of each valve is operated directly or indirectly by thetappet on the piston-rod to shift the weight before mentioned, so thatit will move by gravity beyond the distance which the tappet moves it.

those shown in Spears patent, Fig. 2 showing said mechanism in frontelevation,-Fi g. 3 showing said mechanism in perspective. t

The lines a a denote the top of the cylinderhead. b is the piston-rod,which is hollow for the purpose of receiving a guide-rod, c, preferablymade as a wide thin rectangular bar, which fits a cap, d, secured to thetop end of the piston-rod. By this device of the combination of thehollow piston-rod b with the guide-rod c I am enabled to reduce thespace occupied by the machine in its working to an amount nearly equalto the length of the stroke o f the machine, and in said combination onepart of `my invention consists. e is a piece adjustably fixed on thepiston-rod, and in said piece are secured pins f and g, whichrespectively operate to cause motion of the air-'inlet and air-outletvalves.` Said valves may be of any known kind, but for the purpose Iprefer balance-poppets, and they and the valve-chests and the airinletand outlet valves may be connected to the cylinder-head, or to theupper part of the cylinder, in any convenient location and' by anysuitable means. rIhe stem h is connected to the air-inlet valve, and thesteln t' to the air outlet or exhaust valve. The rocker-arm j is securedto the rocker-shaft 7c, which also has adjustably securedthereunto therocker-arm l, which carries the weight fm, all of said parts bein gVoperative to move the inlet-valve stem h when the tappet f strikes theupper edge of arm j or the lower edge of the lifter n, which is adjustably fixed on the guided rod o,

which is connected to rocker-arm j. The inlet and outlet air-valves areso arranged that when the piston-rod is movin g downward near the lastpart of its stroke the inlet-valve closes, after which the outlet-valveopens; and when the piston-rod rises the outlet-valve is closed nearthe'last part of the upward stroke, and after said valve is closed theinlet-valve is opened. The rocker-arm p is secured to the rocker-shaftq, which also has adjustably secured thereunto the rocker-arm r, whichcarries the weight s, all of said parts being oper ative to move theoutlet or exhaust valve-stem t' when the tappet g strikes the upper edgeof rocker-arm p, or the lower edge of the lifter t, which is adjustablyfixed on the guided rod u, which is connected to the rocker-arm p.

, In the arrangement shown the inlet-valve opens by a downward movementand closes by moving upward, and the outletvalve also opens and closessimilarly.

In Fig. l the position of the parts shown in full lines is that in whichthe piston-rod b is depressed to the greatest extent, the weights m ands being both thrown forward, and the outlet-valve open and theinlet-valve closed, so that, the cylinder being wholly or partlyimmersed in water, the liquid will owin and will-raise thebuoyant'piston until tappet g strikes lifter t, which causes weight s toassume the position shown in dotted lines in Fig. l, which closes theoutlet-valve, after which tappet f', which is ixed in the piece e nearthe piston-rod I), strikes lifter a and causes weight m to assume theposition seen in Fig. l in dotted lines, which opens the inlet-valve,and the compressed air enters the cylinder and expels the water, thepiston in the cylinder descending by its weight until tappet f strikesarm j, which throws wei ght m forward from the position shown in dottedlines to that shown in full lines, Fig. l, closing the air-inlet valve 5and immediately after tappet g strikes arm p and throws weight s forwardfrom the position shown in 'dotted lines to that shown in full lines,Fig. 1, opening the outlet-valve, whereupon the piston in the cylinderbegins to rise, expelling the air contained` above the piston in thecylinder; and thus the mechanism will continue to act so long ascompressed air is supplied.

In mines it is desirable to have this pump located in a sump below thelevel to which the mine is to be kept drained, and while, if theexigencies of the case require, the piston may move through the lengthof the cylinder, as before explained, there are cases and times when itis desirable to lessen the piston-stroke so as to keep thedischarging-action ofthe pump only.equal to or but slightly in excessot' the supply of water, thus using the pump constantly instead ofintermittently, and consuming no more compressed air than is required tokeep the water at or below a convenient level.

To effect the purpose of shortening the distance from the top of thecylinder, which can be lled with compressed air-or, in other words, toshorten the stroke of the pump, and to reduce the quantity of air takento perform each stroke, and to reduce the amount of water delivered byeach stroke-I place on the rods o and a lifters t and w, so arrangedthat they may be adjusted up and down on said rods, and so that they maybe xed where the tappets ff and g will strike them or will pass clear ofthem, as may be desired. It will now be clearly seen that if the litterso and w are turned on the rods o and u so as to be situated similarly tothe lifters a and t, it will be on lifters o and w, and not on lifters uand t, that the tappets f and g operate. Hence the nearerthe lifters vand w are set to the cylin der-head a the shorter will be the stroke ofthe pump and the less will be the quantity of water delivered by eachstroke.'

It should be borne in mind that the function of the piston in thecylinder is merely that of a buoyant loose-fitting lioat, which moveswith the direction of the motion of the water in the cylinder, and withforce sufficient only to move the weights m and s, so that they willfall or tip by gravity. It will also be seen that allot' the litters areso arranged relatively that the outlet-valve is closed before theinlet-valve is opened, and that the inlet-valve is closed before theoutlet-valve is-opened, so that at no time can there be a freecommunication established with the atmosphere through the pump from theair compressor or reservoir.

For convenience in regulating the movement of the valves the weights mand s are made adjustable on the arms l and 1.

I claiml. In an apparatus for delivering liquids under and by the actionthereon of compressed air or gases, the valve-operating mechanismcombined and arranged substantially as shown and described.

2. In combination with said mechanism,the intermediate lifters e and w,arranged as specied.

3. The combination of the hollow piston-rod b with the cap d and guidec, as and for the purpose specified.

JOHN F. HASKINS. Witnesses:

'l'. K. WARE, C. H. B. SNOW.

